Ok, more dumb questions. Any reason that should I shake up my primary fermenter after a week or so or more? I read some blog before that said it will do something but all I can imagine that shaking the primary does is release Co2, big deal. Any thoughts? I all grain if that makes a difference.

The only reason I would even think shaking your primary would do any good is if the yeast isn't taking off and it needs to be shaken to get it suspended in the beer again. I don't know if I'd even shake it then though. I'd probably remove the lid and stir it slowly so I don't oxidize it.

Are you sure you didn't read something about shaking a keg to carbonate it?

Sometimes people who use a highly flocculant yeast will swirl, as opposed to shake, their fermentor to try and resuspend the yeast and continue fermentation. This may get you a couple points lower FG in some situations.

The classic yeast that has this issue is WLP002/WY1968. The other occasion might be if you had an accidental drop in temperature that caused the yeast to drop out. I've found that the swirl has never gained me much of anything, probably because it's very hard to restart fermentation once it's stopped, but others seem to benefit somewhat.

For most yeasts and most fermentations it's really not necessary and very few people do it regularly.

The downside of swirling is that you will probably pick up some material from the krausen ring, which supposedly adds a harsh bitterness to beer.

If you haven't shaken either a primary bucket or a carboy, there is a slight delayed response and then a large release of whatever the the gas is in the yeast cake is, through the air lock, quite violent at times.

Its kind of like when you rack off from the primary yeast cake then the bubbles start to appear through the yeast cake, only faster.

I can't imagine that oxidation would occur, isn't the fermenting gas free of oxygen? If so the fermenting gas should replace the little bit of oxygen that was in the primary before the fermenting process began?

I haven't heard anything about the krausen ring before, that's interesting. I have been reusing the same primary buckets on a few batches for the yeast cake. When I rack off from the brew kettle to the "used primary bucket" I have been scraping the krausen ring off from the bucket with the racking tube back into the primary bucket. Maybe I shouldn't? Thanks for the info!!

I can't see there being a whole lot of air in a plastic bucket while it's fermenting, but they aren't 100% air tight by any means. Better safe than sorry I always say.

Make a starter with good yeast and you'll never need to worry about shaking a fermenter. Even if it did add some benifit to the beer, it's probably so minute that you'd never be able to tell the difference.

Suthrncomfrt1884 wrote:Make a starter with good yeast and you'll never need to worry about shaking a fermenter. Even if it did add some benifit to the beer, it's probably so minute that you'd never be able to tell the difference.